“The gunman entered the bathroom and was shooting his machine gun, so we are all like scrambling around in the bathroom, screaming at the top of our lungs when he was in there for the first time and then, you know, people are getting hit by bullets, like blood is everywhere and then there was a moment where he stopped shooting in the bathroom and that’s when everyone looked around and that’s when I first realized that my leg was shot …

There were several other people shot and bleeding in the bathroom. That’s when Akyra [Monet Murray], who didn’t make it, realized she was shot in her arm … and I’m not sure that was when Tiara also got shot in her thigh but … we were all pretty bad, at that point this is when we knew this wasn’t a game. This was real and this was something that was really happening to us right now.

It was a shock. We went from having the time of our lives to the worst night of our lives all within a matter of minutes.

Throughout that period of hours, the gunman was in there with us. He actually made a call to 911 from in there. Everybody could hear – who was in the bathroom, who survived. We could hear him talking to 911, saying that the reason why he’s doing this is because he wants America to stop bombing his country. From that conversation, from 911, he pledged allegiance to Isis, he started speaking in, I believe … after he get off the phone with 911, he started speaking in Arabic … at first I didn’t know what the language was. And after that, he even spoke to us directly in the bathroom. He said: ‘Are there any black people in here?’ I was too afraid to answer, but there was an African American male in the stall where most of my body was, where a majority of my body was, had answered and he said, ‘Yes, there are about six or seven of us,’ and the gunman responded back to him saying, ‘You know that I don’t have a problem with black people, this is about my country. You guys suffered enough.’

He made a statement saying it wasn’t about black people. This isn’t the reason why he was doing this. But through the conversation with 911, he said that the reason why he was doing this is that he wanted America to stop bombing his country. So, the motive was very clear to us who were laying in our own blood and other people’s blood, who were injured, who were shot. We knew what his motive was and that he wasn’t going to stop killing people until he was killed, until he felt like his message got out there.

First they came for the bloggers, the atheists, the secular intellectuals. Then the three-year murder spree spread to aid workers, minority religions and Muslims who did not want their country reshaped by extremist Islam

The attack on Professor Rezaul Karim Siddiquee was so frenzied that its traces remain more than a month later, arcs of dried blood spattered up a pink wall and a pile of sand covering bloodstains that had pooled on the ground where the softly spoken lecturer was all but beheaded.

He was killed on his way to work in the city of Rajshahi by four men who knew their target and his routines well. At least one of the killers was a former student who had a reputation for barracking the professor in class about the “immorality” of the English literature he taught, police believe.

Neighbours in the narrow alley where Siddiquee was murdered overheard him greet someone moments before his death. “You’re here?” he asked his killer. His final words were spoken in surprise but not fear, because Siddiquee never imagined that he would be a target for extremists, his family says.

The murder fitted into a pattern laid down over a gruesome three-year killing spree by extremist groups in Bangladesh: a bloody but brutal attack in broad daylight with the most basic of weapons, and later a claim of responsibility from Islamic State (Isis) or al-Qaida.

But it was also a warning of the way the killers have expanded their campaign, from a focused assault on secular activists into a wider war to reshape Bangladeshi society along lines determined by Islamist extremists.

Siddiquee was an observant believer who regularly attended prayers and even paid for the renovation of the mosque in his ancestral village – his was the most anodyne of public profiles. If he was a target, surely millions of other Bangladeshis are too.

“What he was, we all are. If a person like him who loves to read, recite literature and play music at home can be killed, all of us are liable to be next,” said one of Siddiquee’s colleagues, asking not to be named for fear it could push him up a list of possible targets.

Foreigners, religious minorities from Hindus to Christians, Muslims from other sects and even Sunnis who subscribe to a more generous vision of faith than their attackers, are all now at risk.

Since 2013, 30 people have been murdered. They were from all faiths and social backgrounds, linked above all by the manner of their deaths, at the hands of men wielding machetes, knives and even swords. At least three others barely escaped assassination attempts, surviving with scars on their faces and necks that look like medieval battle injuries.

One, Ahmed Rahim Tutul (pictured on page 15), survived only because he fell between a table and chair as a militant slashed at his head with a sword in an attack that left terrible scars across his face.